does oxygen delivery matter?

Does oxygen delivery matter?

PiO2

130

PaO2

100

PmO2

2

PAO2

120

PcO2

45PvO2

40

Georg Ohm1789-1854

Die galvanische Kette, mathematisch bearbeitet: 1927

Q

P

Q

Georg Ohm1789-1854

Weil: Circulation 1970

Shoemaker: CHEST 1988

Shoemaker: CHEST 1988

Shoemaker: CHEST 1988

Cardiac failure

↑ Lactate (n=8)↓

Normal lactate (n=28)↓

Sepsis

↑ Lactate (n=16)↓

Normal lactate (n=21)↓

Vincent: ARRD 1990

“Oxygen supply dependency”

Hayes: New Engl J Med 1994

(n=50)

(n=50)

The end of the DO2 debate?

YESUnderstanding in haemodynamic physiologyLimitations of surrogate indicesPreference for non-synthetic catecholamines

NOIndustry-driven therapeutic imperativeIndustry-driven technological imperativeProtagonist-driven studies

Rivers: New Engl J Med 2001

EGDT in sepsis

Angus: Int Care Med 2015

Fifteen years of uncertainty and confusion between the first trial and eventual proof of

absence of benefit

Exposed the adverse influence of industry in investigator-initiated research focused on

surrogate outcomes.

MAP Volume

Stroke volume

ImpedanceCardiac

RAPNeurohormonal vasoregulation

Pressure = Stressing volume Compliance

The physiological fallacy

Cardiac failure

Spectrum of pathology

Compensated Decompensated

Acute

Chronic

Spectrum of treatment

Compensated Decompensated

Neurohormonal modulation Acute

Chronic

Pharmacologicalaugmentation

Cardiac failure

Spectrum of treatment

Compensated Decompensated

Acute

Chronic

ACE inhibitorsAT-II inhibitorsb Blockade

Diuretics

(Fluids)Catecholamines

Diuretics

Cardiac failure

We are happier in many ways when we are old than when we were young. The young sow wild oats. The old grow sage.

Does DO2 matter?